[PATCH 12/17] ARM: mvebu: Armada XP GP specific suspend/resume code
Gregory CLEMENT
gregory.clement at free-electrons.com
Mon Nov 10 05:53:38 PST 2014
Hi Thomas,
[...]
> +#include "common.h"
> +
> +#define ARMADA_XP_GP_PIC_NR_GPIOS 3
> +
> +static void __iomem *gpio_ctrl;
> +static int pic_gpios[ARMADA_XP_GP_PIC_NR_GPIOS];
> +static int pic_raw_gpios[ARMADA_XP_GP_PIC_NR_GPIOS];
> +
> +static void mvebu_armada_xp_gp_pm_enter(void __iomem *sdram_reg, u32 srcmd)
> +{
> + u32 reg, ackcmd;
> + int i;
> +
> + /* Put 001 as value on the GPIOs */
> + reg = readl(gpio_ctrl);
> + for (i = 0; i < ARMADA_XP_GP_PIC_NR_GPIOS; i++)
> + reg &= ~BIT(pic_raw_gpios[i]);
> + reg |= BIT(pic_raw_gpios[0]);
> + writel(reg, gpio_ctrl);
> +
> + /* Prepare writing 111 to the GPIOs */
> + ackcmd = readl(gpio_ctrl);
> + for (i = 0; i < ARMADA_XP_GP_PIC_NR_GPIOS; i++)
> + ackcmd |= BIT(pic_raw_gpios[i]);
> +
> + /* Wait a while */
> + mdelay(250);
> +
> + asm volatile (
> + /* Align to a cache line */
> + ".balign 32\n\t"
> +
> + /* Enter self refresh */
> + "str %[srcmd], [%[sdram_reg]]\n\t"
> +
> + /* Wait 100 cycles for DDR to enter self refresh */
> + "1: subs r1, r1, #1\n\t"
I should miss something obvious, but I don't see where you load 100 in
the r1 register. According to your comment and the code, you remove 1 from
r1 until it reaches 0, so I expected that just before you have loaded 100 in r1.
Thanks,
Gregory
> + "bne 1b\n\t"
> +
> + /* Issue the command ACK */
> + "str %[ackcmd], [%[gpio_ctrl]]\n\t"
> +
> + /* Trap the processor */
> + "b .\n\t"
> + : : [srcmd] "r" (srcmd), [sdram_reg] "r" (sdram_reg),
> + [ackcmd] "r" (ackcmd), [gpio_ctrl] "r" (gpio_ctrl) : "r1");
> +}
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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